I have just seen a very large UFO over New Barnet in London England; I saw the UFO at around 2.40 pm GMT and watched it for around 25 minutes. The UFO was large bigger than a 747 aircraft, it was black diamond shape, and it did change into a tube shape, than back again. It just hovered from left to right at about 250 feet, no sound but many airliners flew near to it as this part of London has many air routes over it, they must have seen something. I’ve just looked on the internet for a number or website to report this in Britain, couldn’t find one, sorry to trouble you, but I just had to report this.